Multilayer circuit board structure
By using a combination of blind vias and through-holes in a multilayer circuit board design, efficient electrical connections between conductive layers are achieved, solving the space occupation problem of through-holes and improving wiring density and production quality.
Patent Information
- Application Number
- CN202422445786.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2025-10-31
- Estimated Expiration
- 2034-10-10
AI Technical Summary
In existing multilayer circuit board structures, through-holes occupy a lot of space when connecting conductive layers to electronic components, which limits high-density wiring design.
The design combines blind and through holes, and the electrical connection between conductive layers is achieved through a conductive coating, avoiding space occupation on the substrate. Opaque markings are set on the conductive layers to ensure accuracy and production quality.
It increases the wiring density of conductive lines, reduces the space occupied by multi-layer circuit boards, optimizes the interconnection of conductive layers, and improves production quality.
Smart Images
Figure CN223503102U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of printed circuit board technology, and in particular to a multilayer circuit board structure. Background Technology
[0002] Circuit boards are the fundamental structures in electronic devices used to mount and connect electronic components. They typically achieve electrical connections and signal transmission between components by printing conductive paths and pads onto an insulating substrate. Currently, single-layer boards are commonly used. However, single-layer boards, with only one layer of copper foil, have limited wiring space, making them unsuitable for handling complex circuits and high-density component placement; they cannot meet the demands of highly integrated, high-functionality circuits and are only suitable for simple electronic products. Multilayer boards (commonly four-layer or six-layer boards) also exist. Multilayer boards can have multiple conductive layers, providing more wiring space and are suitable for complex circuits and high-density component placement. However, multilayer boards typically mount and connect electronic components on one side of the soldering surface. When connecting conductive layers to electronic components or between conductive layers, existing solutions often use through-holes. These through-holes penetrate all layers, occupying significant board space and limiting the design of high-density wiring. Utility Model Content
[0003] The purpose of this invention is to provide a multi-layer circuit board structure that aims to increase the wiring density of conductive lines and reduce the space occupied by the multi-layer circuit board structure.
[0004] To achieve this objective, the present invention adopts the following technical solution:
[0005] A multilayer circuit board structure includes a first substrate, a second substrate, and a third substrate stacked sequentially; a first conductive layer is provided on the upper surface of the first substrate, a second conductive layer is provided between the first substrate and the second substrate, a third conductive layer is provided between the second substrate and the third substrate; and a fourth conductive layer is provided on the lower surface of the third substrate.
[0006] The multilayer circuit board structure also forms a first blind hole penetrating the first substrate, a second blind hole penetrating the first substrate and the second substrate in sequence, and a first through hole penetrating the first substrate, the second substrate and the third substrate in sequence; the walls of the first blind hole, the second blind hole and the first through hole are all provided with a conductive coating.
[0007] In one embodiment, the first substrate, the second substrate, and the third substrate are all semi-transparent materials;
[0008] The first conductive layer, the second conductive layer, the third conductive layer, and the fourth conductive layer are all provided with opaque markings;
[0009] When the first conductive layer, the first substrate, the second conductive layer, the second substrate, the third conductive layer, the third substrate, and the fourth conductive layer are stacked in sequence, multiple light-transmitting marks can be combined to form a specific pattern.
[0010] In one embodiment, the multilayer circuit board structure is a four-layer board;
[0011] In one embodiment, the opaque mark is in the shape of a right-angled sector, and the specific pattern is a circle.
[0012] In one embodiment, the opaque mark is an isosceles triangle and the specific pattern is a rectangle.
[0013] In one embodiment, the shape of the opaque mark is an equally divided square, and the specific pattern is a rectangle.
[0014] In one embodiment, both the opaque marking and the conductive circuit are made of copper.
[0015] In one embodiment, a fixture plate is further included, which is stacked above the first conductive layer or stacked below the fourth conductive layer; the fixture plate has a light-transmitting portion through which the opaque mark can be observed.
[0016] In one embodiment, the multilayer circuit board structure further includes at least one first via for mounting a guide structure; the first via penetrates the first conductive layer, the first substrate, the second conductive layer, the second substrate, the third conductive layer, the third substrate, and the fourth conductive layer.
[0017] In one embodiment, the system further includes a first protective layer and a second protective layer, wherein the first protective layer is stacked on top of the first conductive layer and the second protective layer is stacked below the fourth conductive layer.
[0018] In one embodiment, the system further includes a first adhesive layer and a second adhesive layer, wherein the first adhesive layer is stacked between the first substrate and the second substrate; and the second adhesive layer is stacked between the second substrate and the third substrate.
[0019] In one embodiment, the first adhesive layer is made of epoxy resin.
[0020] In one embodiment, the multilayer circuit board structure is a six-layer board.
[0021] Compared with the prior art, the present invention has the following beneficial effects:
[0022] In this invention, the first blind via penetrates the first substrate and reaches the second substrate, so that the conductive coating of the first blind via is electrically connected to the conductive lines of the second conductive layer. The first blind via avoids occupying space on the second and third substrates, thereby increasing the wiring density of the conductive lines in the third and fourth conductive layers, and thus reducing the space occupied by the multilayer circuit board structure. The second blind via sequentially penetrates the first and second substrates and reaches the third substrate, so that the conductive coating of the second blind via is electrically connected to the conductive lines of the third conductive layer. The second blind via avoids occupying space on the third substrate, thereby increasing the wiring density of the conductive lines in the fourth conductive layer, and thus reducing the space occupied by the multilayer circuit board structure. Attached Figure Description
[0023] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0024] The structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this utility model. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and purposes that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.
[0025] Figure 1 This is a schematic diagram of an embodiment of the multilayer circuit board structure of this utility model;
[0026] Figure 2 This is a schematic diagram of an embodiment of the opaque marking of this utility model;
[0027] Figure 3 This is a schematic diagram of an embodiment of the opaque marking of this utility model;
[0028] Figure 4 This is a schematic diagram of an embodiment of the opaque marking of this utility model;
[0029] Figure 5 This is a schematic diagram of an embodiment of the fixture plate of this utility model;
[0030] Illustration: 100. Multilayer circuit board structure;
[0031] 111. First substrate; 112. Second substrate; 113. Third substrate;
[0032] 121. First conductive layer; 122. Second conductive layer; 123. Third conductive layer; 124. Fourth conductive layer;
[0033] 131. First protective layer; 132. Second protective layer;
[0034] 141. First adhesive layer; 142. Second adhesive layer;
[0035] 151. First blind via; 152. Second blind via; 153. First through-hole; 154. First via; 155. Metal pad;
[0036] 160. Specific patterns; 161. Opaque markings;
[0037] 170. Jig plate; 171. Translucent part. Detailed Implementation
[0038] To make the technical objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.
[0039] In the description of this utility model, it should be understood that the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. It should be noted that when a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.
[0040] The technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.
[0041] This utility model embodiment provides a multilayer circuit board structure 100. For example... Figure 1 As shown, for ease of description, the side of the first substrate 111 relative to the second substrate 112 is defined as the upper side, and the side of the third substrate 113 relative to the second substrate 112 is defined as the lower side.
[0042] Please see Figure 1 In one embodiment of the present invention, the multilayer circuit board structure 100 includes: a first substrate 111, a second substrate 112 and a third substrate 113; and a first conductive layer 121, a second conductive layer 122, a third conductive layer 123 and a fourth conductive layer 124 respectively disposed with conductive lines.
[0043] A first substrate 111, a second substrate 112, and a third substrate 113 are stacked sequentially; a first conductive layer 121 is disposed on the upper surface of the first substrate 111, a second conductive layer 122 is disposed between the first substrate 111 and the second substrate 112, a third conductive layer 123 is disposed between the second substrate 112 and the third substrate 113; and a fourth conductive layer 124 is disposed on the upper surface of the third substrate 113.
[0044] The multilayer circuit board structure 100 also forms a first blind hole 151, a second blind hole 152, and a first through hole 153. The first blind hole 151, the second blind hole 152, and the first through hole 153 are all provided with a conductive coating on their inner walls.
[0045] The first blind via 151 penetrates the first substrate 111 and reaches the second substrate 112, so that the conductive coating of the first blind via 151 is electrically connected to the conductive lines of the second conductive layer 122.
[0046] The second blind via 152 passes through the first substrate 111 and the second substrate 112 in sequence and reaches the third substrate 113, so that the conductive coating of the second blind via 152 is electrically connected to the conductive lines of the third conductive layer 123.
[0047] The first through-hole 153 passes through the first substrate 111, the second substrate 112 and the third substrate 113 in sequence, so that the conductive coating of the first through-hole 153 is electrically connected to the conductive lines of the fourth conductive layer 124.
[0048] It is understood that in the technical solution of this utility model, the first blind via 151 penetrates through the first substrate 111 and reaches the second substrate 112, so that the conductive coating of the first blind via 151 is electrically connected to the conductive lines of the second conductive layer 122. The arrangement of the first blind via 151 avoids occupying space on the second substrate 112 and the third substrate 113, thereby increasing the wiring density of the conductive lines of the third conductive layer 123 and the fourth conductive layer 124, and thus reducing the space occupied by the multilayer circuit board structure 100. The second blind via 152 sequentially penetrates through the first substrate 111 and the second substrate 112 and reaches the third substrate 113, so that the conductive coating of the second blind via 152 is electrically connected to the conductive lines of the third conductive layer 123. The arrangement of the second blind via 152 avoids occupying space on the third substrate 113, thereby increasing the wiring density of the conductive lines of the fourth conductive layer 124, and thus reducing the space occupied by the multilayer circuit board structure 100.
[0049] It is also understandable that when it is necessary to achieve arbitrary interconnection of conductive layers of multilayer circuit board structure 100, optionally, a first pad that is electrically connected to the conductive line of the first conductive layer 121 can be provided at the position of the first blind hole 151 corresponding to the first conductive layer 121, so as to achieve electrical connection between the first conductive layer 121 and the second conductive layer 122.
[0050] Optionally, by providing a second pad that is electrically connected to the conductive lines of the first conductive layer 121 at the position of the second blind hole 152 corresponding to the first conductive layer 121, the first conductive layer 121 and the third conductive layer 123 can be electrically connected.
[0051] Optionally, by providing a third pad that is electrically connected to the conductive lines of the first conductive layer 121 at the position of the first through hole 153 corresponding to the first conductive layer 121, the first conductive layer 121 and the fourth conductive layer 124 can be electrically connected.
[0052] Optionally, by providing a fourth pad that is electrically connected to the conductive lines of the second conductive layer 122 at the position of the second blind hole 152 corresponding to the second conductive layer 122, the electrical connection between the second conductive layer 122 and the third conductive layer 123 can be achieved.
[0053] Optionally, by providing a fifth pad that is electrically connected to the conductive lines of the third conductive layer 123 at the position of the first through hole 153 corresponding to the third conductive layer 123, the electrical connection between the third conductive layer 123 and the fourth conductive layer 124 can be achieved.
[0054] It is understood that the overall structure of the multilayer circuit board structure 100 remains unchanged, with no alterations to the electrical connections between the first conductive layer 121 and the second conductive layer 122, the first conductive layer 121 and the third conductive layer 123, the first conductive layer 121 and the fourth conductive layer 124, the second conductive layer 122 and the third conductive layer 123, and the third conductive layer 123 and the fourth conductive layer 124. The change lies in the arrangement of the conductive lines in each conductive layer (the addition of solder pads). It is also understood that the conductive lines and solder pads are formed in the same processing step. Therefore, the technical solution of this invention can also achieve interconnection of any conductive layer, thereby further optimizing the wiring density of the conductive lines in each conductive layer and reducing the space occupied by the multilayer circuit board structure 100.
[0055] In one specific embodiment, the thickness of the conductive lines in the first conductive layer 121, the second conductive layer 122, the third conductive layer 123, and the fourth conductive layer 124 is 0.01 mm.
[0056] Optionally, the conductive lines are made of copper.
[0057] Optionally, the thickness of the conductive lines in the second conductive layer 122 is 0.012 mm; and the thickness of the conductive lines in the third conductive layer 123 is 0.008 mm.
[0058] In one specific embodiment, the thickness of the first substrate 111, the second substrate 112, and the third substrate 113 is 0.1 mm; the material of the first substrate 111, the second substrate 112, and the third substrate 113 is glass fiber epoxy resin.
[0059] Please see Figures 1 to 4 In a preferred embodiment of the present invention, the first substrate 111, the second substrate 112, and the third substrate 113 are all semi-transparent materials.
[0060] The first conductive layer 121, the second conductive layer 122, the third conductive layer 123, and the fourth conductive layer 124 are all provided with opaque markings 161;
[0061] When the first conductive layer 121, the first substrate 111, the second conductive layer 122, the second substrate 112, the third conductive layer 123, the third substrate 113 and the fourth conductive layer 124 are stacked in sequence, multiple light-transmitting marks can be combined to form a specific pattern 160.
[0062] It is understandable that the first substrate 111, the second substrate 112 and the third substrate 113 are made of glass fiber epoxy resin, and glass fiber epoxy resin material has a certain degree of light transmittance.
[0063] It should be noted that, in the present invention, since there are multiple conductive layers, when each conductive layer is stacked, the position of the conductive line on each conductive layer must correspond to the position of the first blind hole 151, the second blind hole 152, and the first through hole 153, respectively. This ensures that after the drilling and electroplating processes are performed on the first blind hole 151, the second blind hole 152, and the first through hole 153, the circuit between the first blind hole 151, the second blind hole 152, and the first through hole 153 and the second conductive layer 122, the third conductive layer 123, and the fourth conductive layer 124, respectively, can be effectively connected.
[0064] Therefore, to ensure that the positions of the conductive lines on each conductive layer correspond to the positions of the first blind via 151, the second blind via 152, and the first through via 153, opaque markings 161 are provided on the first conductive layer 121, the second conductive layer 122, the third conductive layer 123, and the fourth conductive layer 124, respectively. Specifically, the material of the opaque markings 161 in each conductive layer is the same as the material of the conductive lines in each conductive layer. Therefore, the opaque markings 161 and the conductive lines in each conductive layer can be processed in the same step. Thus, the setting of the opaque markings 161 can improve the production quality of the multilayer circuit board structure 100 without increasing the additional cost.
[0065] Specifically, after the first conductive layer 121, the first substrate 111, the second conductive layer 122, the second substrate 112, the third conductive layer 123, the third substrate 113, and the fourth conductive layer 124 are sequentially stacked, if the pattern formed by the combination of multiple light-transmitting marks conforms to the shape of a specific pattern 160, it indicates that the precision positioning of the multilayer circuit board structure 100 meets the production quality requirements. If the pattern formed by the combination of multiple light-transmitting marks does not conform to the shape of the specific pattern 160, it indicates that the precision positioning of the multilayer circuit board structure 100 does not meet the production quality requirements, and the product is considered defective.
[0066] like Figure 2 As shown, in one embodiment, the opaque mark 161 is shaped like a right-angled sector, and the specific pattern 160 is circular. After multiple translucent marks are combined to form a pattern, the observed pattern is... Figure 2 When a, it is considered not to conform to the specific pattern 160 shape; the observed pattern is Figure 2 When b, it is considered to conform to the specific pattern 160 shape.
[0067] like Figure 3 As shown, in one embodiment, the shape of the opaque mark 161 is an isosceles triangle. Figure 3 'a' indicates that the shape does not conform to the specific pattern 160. Figure 3 b indicates a specific pattern; 160 represents a rectangle.
[0068] like Figure 4 As shown, in one embodiment, the opaque mark 161 is a square with equal divisions. Figure 4 'a' indicates that the shape does not conform to the specific pattern 160. Figure 4 b indicates a specific pattern; 160 represents a rectangle.
[0069] Optionally, the opaque marking 161 and the conductive lines are made of copper.
[0070] Please see Figure 1 and Figure 5In a specific embodiment of this utility model, a fixture plate 170 is also included. The fixture plate 170 is stacked above the first conductive layer 121 or below the fourth conductive layer 124. The fixture plate 170 has a light-transmitting portion 171 through which the opaque mark 161 can be observed.
[0071] Understandably, the light-transmitting portion 171 is provided on the jig plate 170 to facilitate quick observation of the opaque marking 161. Optionally, the jig plate 170 is made of opaque material, and the light-transmitting portion 171 is either a vent or a light-transmitting lens.
[0072] Furthermore, such as Figure 5 As shown, the multilayer circuit board structure 100 also has at least one first via 154 for mounting a guide structure; the first via 154 penetrates the first conductive layer 121, the first substrate 111, the second conductive layer 122, the second substrate 112, the third conductive layer 123, the third substrate 113 and the fourth conductive layer 124.
[0073] Understandably, the first via 154 is primarily for guiding the stacking of the substrates and the fixture plate 170, so that the light-transmitting portion 171 can be quickly aligned with the opaque mark 161.
[0074] Please continue reading Figure 1 In one specific embodiment of this utility model, the multilayer circuit board structure 100 further includes a first protective layer 131 and a second protective layer 132. The first protective layer 131 is stacked on top of the first conductive layer 121; the second protective layer 132 is stacked below the fourth conductive layer 124. It is understood that the protective layers are provided to prevent the conductive circuit pattern from being damaged during etching or electroplating. Optionally, the first protective layer 131 and the second protective layer 132 are made of epoxy resin ink or photosensitive polymer ink.
[0075] It is also understandable that the first protective layer 131 is designed to avoid the metal pads 155 in the conductive lines of the first conductive layer 121.
[0076] Optionally, the first protective layer 131 and the second protective layer 132 can also avoid the pads near the edges of the first blind hole 151, the second blind hole 152 and the first through hole 153.
[0077] Furthermore, the multilayer circuit board structure 100 also includes a first adhesive layer 141 and a second adhesive layer 142. The first adhesive layer 141 is stacked between the first substrate 111 and the second substrate 112; the second adhesive layer 142 is stacked between the second substrate 112 and the third substrate 113.
[0078] Understandably, the adhesive layer enhances the mechanical strength and heat dissipation performance of the multilayer circuit board structure 100.
[0079] Optionally, the first adhesive layer 141 is made of epoxy resin.
[0080] Optionally, under the same technical concept, when five substrates and six conductive layers are provided, the multilayer circuit board structure 100 is a six-layer board.
[0081] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.
Claims
1. A multilayer circuit board structure, characterized in that, include: A first substrate, a second substrate, and a third substrate are stacked sequentially; a first conductive layer is provided on the upper surface of the first substrate, a second conductive layer is provided between the first substrate and the second substrate, a third conductive layer is provided between the second substrate and the third substrate; a fourth conductive layer is provided on the lower surface of the third substrate. The multilayer circuit board structure also forms a first blind hole penetrating the first substrate, a second blind hole penetrating the first substrate and the second substrate in sequence, and a first through hole penetrating the first substrate, the second substrate and the third substrate in sequence; the walls of the first blind hole, the second blind hole and the first through hole are all provided with a conductive coating.
2. The multilayer circuit board structure according to claim 1, characterized in that, The first substrate, the second substrate, and the third substrate are all semi-transparent materials; The first conductive layer, the second conductive layer, the third conductive layer, and the fourth conductive layer are all provided with opaque markings; When the first conductive layer, the first substrate, the second conductive layer, the second substrate, the third conductive layer, the third substrate, and the fourth conductive layer are stacked in sequence, multiple light-transmitting marks can be combined to form a specific pattern.
3. The multilayer circuit board structure according to claim 2, characterized in that, The multilayer circuit board structure is a four-layer board; The opaque mark is in the shape of a right-angled sector, and the specific pattern is circular; or, The opaque mark is in the shape of an isosceles triangle, and the specific pattern is a rectangle; or, The opaque mark is in the shape of an equally divided square, and the specific pattern is a rectangle.
4. The multilayer circuit board structure according to claim 2, characterized in that, Conductive lines are disposed on the first conductive layer, the second conductive layer, the third conductive layer and the fourth conductive layer, and the opaque mark and the conductive lines are both made of copper.
5. The multilayer circuit board structure according to claim 2, characterized in that, It also includes a fixture plate, which is stacked above the first conductive layer or stacked below the fourth conductive layer; the fixture plate has a light-transmitting portion through which the opaque mark can be observed.
6. The multilayer circuit board structure according to claim 5, characterized in that, The multilayer circuit board structure also has at least one first via for mounting a guide structure; the first via penetrates the first conductive layer, the first substrate, the second conductive layer, the second substrate, the third conductive layer, the third substrate, and the fourth conductive layer.
7. The multilayer circuit board structure according to any one of claims 1 to 2, 4 to 6, characterized in that, It also includes a first protective layer and a second protective layer, wherein the first protective layer is stacked on top of the first conductive layer; and the second protective layer is stacked below the fourth conductive layer.
8. The multilayer circuit board structure according to claim 7, characterized in that, It also includes a first adhesive layer and a second adhesive layer, wherein the first adhesive layer is stacked between the first substrate and the second substrate; and the second adhesive layer is stacked between the second substrate and the third substrate.
9. The multilayer circuit board structure according to claim 8, characterized in that, The first adhesive layer is made of epoxy resin.
10. The multilayer circuit board structure according to claim 7, characterized in that, The aforementioned multilayer circuit board structure is a six-layer board.